It always depends according to your preference, even if it's just a general non-restrictive faction deck. There's that deck that focus mainly on buffs, others debuffs, or can be a mixture of both. For budget build deck, there's always the "Passcode Deck" where every followers in your field with same size buffs a lot at same time. There's also this "Normal Deck" featuring some mixture of both buffing and debuffing like Disappearance spell, etc. There's also the "Pure Debuff Deck" where everything is focused in burning enemy HP and/or destroying enemy followers in a single move. There's also (aside from those 3 aforementioned decks) the special type decks where focused on something else (locking enemy field, stalling, etc.). So in the end, it depends on your build, if you want your deck to be the "best". As for low budget deck, I will suggest Passcode Deck.
Answer for Q2:
Pretty much dead for NA/INT servers, since this is already locked on KR. Dunno if this game is still available on JP server.
@KuRoNeKo That notice is over a year old (and is out-of-date anyway - there have been updates since then). It's also mistaken in multiple ways:
The pajama characters were already in the game and available before that update, they're just technically EP14 cards.
The pajama characters are obtained via the cafe, not the (currently missing) coin shop.
Sorry, I'm not too familiar with the 100dp format, most of my experience comes from 250-300dp decks. My general impression was that passcode swarm was the most popular deck and comprised of the majority of the metagame.
If snowball/multi-follower buff decks are popular, then yes, this deck will have a field day with them. If the majority of the metagame at 100dp are these kinds of buff decks, I can see why the op would think this deck is one of the best, since it does counter them easily. The deck isn't the strongest by far, but it does fit into the metagame.
@Akihito I'd say those ranges are mostly accurate. There are a few dungeons I'd like to make additional comments about. I'll also point out any where making a specific counter for a given boss would drastically change the requirements.
I would also like to re-emphasise your point (for anyone reading this) that the listed values assume a well-built deck.
2S Agency: consistent clears at 100DP sounds plausible, but we're probably talking a 100DP deck using cards that'd be difficult to reasonably obtain without already having a higher DP deck. If anyone has an example of a 100DP deck that proves me wrong though please share it. This dungeon is fairly inconsistent in general and very slow even considering how many floors it has.
Witch's Tower: the boss is disproportionately difficult for a lot of decks compared to the rest of the dungeon and compared to most season 1 normal dungeons, but also really struggles against certain other decks. The DP required to consistently beat her would be substantially higher than 250 if you're not running a deck that just happens to be effective against her. On the other hand she can be consistently counterdecked at 100DP. The rest of the dungeon can reasonably be done at 100DP.
Vita Public School: the boss matchup varies a lot based on how dependent on skills the deck is. The given values seem accurate for a deck that is at least tweaked for the boss, even if not specifically built for it.
Vivid World: the non-boss floors are unusually difficult and the boss is rather inconsistent.
Catacombs: the difficulty of the boss can vary a lot depending on which followers her effect revives.
Catch That Cat!: the boss is much harder than the rest of the dungeon (which can be cleared at 100DP). The boss can be beaten with a 300DP field lock deck, though this obviously takes ages and is not the same deck you'd use for the previous floors. The boss is notoriously inconsistent even for very high DP decks.
Dimensional Rift: has very hard non-boss floors. The boss can be field locked at 300DP but a strong deck is needed to even reach the boss.
Linia's World: the difficultly of the non-boss floors is highly erratic but floors 31-39 are harder than most bosses. The boss can be field locked at 300DP but again a strong deck is needed to even reach the boss. The boss is inconsistent with any deck that isn't at least heavily tweaked for her (ignoring the possibility of someone coincidentally running something that's a good match for her already). Even if a player has a way to consistently clear all the floors this dungeon is very slow and is not worth farming for accessories - 10th clear reward and bragging rights/showing off only!
I'm curious as to what grinding deck you'd use Amrita (Underground Library boss card) for, since you marked her and Anj Inyghem (Vampire Lands boss card) as only for grinding purposes. Also I wouldn't even suggest Anj for grinding - with the nerf to the final part of Anj's skill (the formerly infamous 'Anjecute') Fugitive Iri Flina (Darklore starter deck character) is generally preferable.
Interesting, and I appreciate the info, and the team who's working on SG.net. Hope I didn't come off as crass with this kind of suggestion. At the very least, I'll pad out some of the fan art archives on the web, and of course Discord. ^ ^
@Akihito, you might want to fix your formatting, parts of your post turned into code blocks.
Increasing your chances of having a decent mix of spells and followers is part of why guaranteeing you have a follower on the field is a pro. More slots for spells isn't necessarily a pro in this case (I'd say it's neither a pro nor a con) since you're playing cards more slowly and hence drawing fewer cards (you're not playing more spells). You increase the variety of spells in the deck but actually decrease the consistency of drawing any particular spell.
You do typically lose some buffing with Alchemist Clarice since if the Homunculus survives you can't continue buffing an already buffed Homunculus. It is possible though the new Homunculus might have more STA if the old one barely survived, and being a Rookie target does make the new Homunculus easier to buff. You do however always have an unbuffed follower on the field at the start of the turn whereas without Clarice you can potentially end a turn with all of your buffed followers surviving, particularly when buffed followers from a previous turn can help newly buffed follower survive by destroying opposing followers more easily (or if an NPC randomly plays an all-spell field or a field that fails to do any damage, since this thread is primarily about grinding decks).
Not saying Alchemist Clarice is bad (she definitely improves the consistency ofgetting a mix of followers and buffs), but she does hurt your ability to maintain a field. Street Idol Clarice is a somewhat different story since her Homunculi have stats similar to an already buffed follower on early turns. Again though we're in the teritory of making a PvP version of a deck that functions best as a cheap grinding deck (transformations are not cheap and there's a lot else you can make with the materials requires to make ~200 1pt commons). If someone is going to make a transformation to use with a size 1 Passcode deck though then I'll agree that Dress Luthica is also a good option (though she doesn't work well with Rookie's Debut).
No news about the new ep, last I heard it's still only 1 person working on it in their spare time (afaik anyone else is too busy irl).